Test of statistical stability of the electroencephalogram

The stability of the EEG during eyes closed and eyes open were tested by the statistical method. The EEG records of 25 s were segmented into ten 2.5 s intervals for each state. The mean and variance and power spectra (2.5 to 17.5 Hz at resolution of 2.5 Hz) were calculated for each segment of 2.5 s interval. Thus, the sequences of mean values, variances and power at each frequency component were obtained for 25 s epoch. The stationarity of these sequences were tested by the run test and the trend test. The stationarity of mean, variance and power spectra were not rejected for 25 s records by any of two tests. In the records of 50 s, about 10–20% of records tested were rejected. The nonstationarity of the EEG appeared for 50 s records. This means that the EEG during period the eyes were closed, or opened can be regarded as stationary over time period as long as at least 25 s.     

Nonstationary power spectrum analysis of the photic alpha blocking

The dynamics of the EEG activity under light stimulation was investigated in terms of the nonstationary power spectrum method. The alpha wave was blocked by light stimulation, however the blocking was temporary, and the alpha activity recovered to that of the resting state even though under light. Moreover the alpha rhythm was also blocked by light off. The frequencies of the preand post-blocked activity were different. The frequency of the post-blocked wave shifted gradually downward and became stable after 3–4 sec.     

Streptococcal immunoglobulin-binding protein Sib35 exerts stimulatory and mitogenic effects toward mouse B lymphocytes

Group A Streptococcus (GAS) produces several immunopotent proteins such as the immunoglobulin-binding protein 35 (Sib35) family, known to be an immunoglobulin G-degrading enzyme of GAS and a CD16-binding protein of GAS, Mac-1-like protein/IdeS. In this study, Sib35 activated mouse B cells and induced the proliferation of B lymphocytes, while it also bound directly to B cells, which enhanced the expression of MHC class II and B7-2. Furthermore, Sib35 induced the differentiation of B cells to immunoglobulin-producing plasma cells and B cell line proliferation. These results suggest that Sib35 functions as a streptococcal mitogen of mouse B cells.     

In Vitro Antibiotic Susceptibilities of Borrelia Isolates from Erythema Migrans Lesion of Lyme Disease Patients in Japan

Antibiotic susceptibilities of twelve borrelial isolates from skin of patients with erythema migrans (EM) and ticks (Ixodes persulcatus and I. ovatus) in Japan were examined by in vitro microdilution MIC method and macrodilution MBC method. Nine EM isolates and 3 tick isolates were susceptible to amoxicillin, erythromycin, and minocycline. MICs for Japanese isolates were 0.038–0.30 μg/ml, < 0.012 μg/ml, and < 0.012–0.05 μg/ml, respectively. MBCs were as follows: 0.038–0.88 μg/ml, < 0.012–0.10 μg/ml, and <0.025–0.78 μg/ml, respectively. These antibiotics could be recommended for treatment of patients in early stage of Lyme disease in Japan.     

Antigenic determinants on fimbriae of Serratia marcescens US5 analyzed using monoclonal antibodies

The antigenic sites on small thin fimbriae of Serratia marcescens strain US5 were investigated using immunoelectron microscopy and monoclonal antibodies (MAbs). Negative staining of the fimbriae after treatment with MAbs showed a regularly spaced arrangement of the antibody molecules. When the subunit peptide was subjected to immunoblotting using the MAbs, a single band with a molecular weight of approximately 19kD was evident. This binding of the MAbs to the subunit peptide was completely abrogated after treatment with 2-mercaptoethanol, thereby suggesting the important role of disulfide linkage in the maintenance of the conformation of the antigenic site reacted with MAbs. Amino acid analysis of the subunit peptide revealed two cysteine residues, and cysteine residues were absent in the N-terminal portion.     

Significance of exercise and bed rest in pregnancy--pregnancy and walking (1)

Prior to evaluating the significance of bed rest in managing obstetric diseases, characteristics of physiology of pregnant women were examined on the basis of 24 hours heart rate changes in eight pregnant women at the third trimester and also distances covered in walking by a total of 53 multiparas and of 87 primiparas during free-living daily activities were measured by means of a pedometer. A significantly higher mean heart rate was observed in those pregnant women even during sleep than in non-pregnant control. The primiparas showed significant decreases in the pedometer readings in all stages except for 15-27 weeks of gestation, while the multiparas of less than 28 weeks exhibited no decrease as compared with non-pregnant control. The decrease in the pedometer readings were marked in both primiparas and multiparas, the value being much lower than that of any other week of gestation. However, the equation of weight x distance covered in walking remains rather constant throughout gestation.